Garage Loads on Retaining Wall

[Bammer25]

Just making sure my thinking is not off here. I have a rear garage wall that is about 12 feet tall from footing up to garage slab. Will be filled with no 57 stone and slab on grade poured on top for garage.

The wall is 26 feet long spanning between perpendicular walls. They plan to tie the wall into the slab by turning the dowels. My questions are:

Do you guys typically do a generic 40 psf live load for the garage per ASCE 7-16 or do you look at concentrated tire loads?

Do you consider the slab to be a support (a box supported on all 4 sides) or just consider the footing and the two perpendicular walls as supports (3 sides).

There is no backfill outside the wall. All of the hydrostatic pressure is just from the stone underneath the garage slab.

 

[Bammer25]

Surprised to see bending about the vertical axis controls over traditional cantilever wall bending

 

[XR250]

In these cases, I generally use a suspended slab. Seems to be cheaper than the gravel and giant-ass retaining wall. Also, provides a no-cost storm shelter. I use the distributed loads, not the conc. tire loads.

 

[Bammer25]

Thank you. That would be cool. I don’t think I’ve seen a true structural slab in residential. Maybe I’ll ask the contractor if he prefers that